NCERT Exercise 9.2 Question 1
Rational Numbers 7th Math
NCERT Exercise 9.2 Question 1
In this chapter, we will learn mathematical operations on rational numbers. In Question Number 1 of the chapter of NCERT Exercise 9.2, math, class seven, there are seven questions. In these questions, the sum of given rational numbers is to find.
Exercise on Operations on Rational Numbers
Operations on Rational Numbers, such as addition, subtraction, multiplication, and division are nothing, only these are similar to operations on fractions.
Solution of NCERT Exercise 9.2
Question (1) Find the sum:
(i) 5/4 + (– 11/4)
Solution :
Given, 5/4 + (– 11/4)
After removal of brackets, we get
5/4 – 11/4
Now, take the LCM of denominators and do required operations similar to fractions
= 5 – 11/4
= – 6/4
Now, the simplest form of obtained rational number
= – 2 × 3/2 × 2
= – 3/2 Answer
Question (1) (ii) 5/3 + 3/5
Solution :
Given, 5/3 + 3/5
Now, the LCM of denominators of given rational numbers = 3 × 5 =15
= (5 × 5) + (3 × 3)/15
= 25 + 9/15
= 34/15
Since there are no common factors other than 1 in the numerator and denominator
Thus, = 34/15 Answer
Question (1) (iii) – 9/10 + 22/15
Solution :
Given, – 9/10 + 22/15
The LCM of denominators of given rational numbers = 30
= (– 9 × 3) + (22 × 2)/30
= – 27+44/30
= 17/30
Since there are no common factors other than 1 in the numerator and denominator
Thus, 17/30 Answer
Question (1) (iv) – 3/ – 11 + 5/9
Solution :
Given, – 3/– 11 + 5/9
= 3/11 + 5/9
The LCM of denominators of given rational numbers = 11 × 9 = 99
= 3 × 9 + 5 × 11/99
= 27 + 55/99
= 82/99
Since there are no common factors other than 1 in the numerator and denominator
Thus, 82/99 Answer
Question (1) (v) – 8/19 + – 2/57
Solution :
Given, – 8/19 + – 2/57
= – 8/19 – 2/57
The LCM of denominators of given rational numbers = 57
= – 8 × 3 – 2 × 1/57
= – 24 – 2/57
= – 26/57
Since there are no common factors other than 1 in the numerator and denominator
Thus, – 26/57 Answer
Question (1) (vi) – 2/3 + 0
Solution :
Given, – 2/3 + 0
We know that we get the same number when we add 0 zero to a number
Thus, = – 2/3 Answer
(vii) – 2 1/3 + 4 3/5
Solution :
Given, – 2 1/3 + 4 3/5
Given rational numbers are in the form of mixed fractions, thus their form of simple fraction
= – 7/3 + 23/5
Now, the LCM of denominators of obtained rational number = 15
= (– 7 × 5) + (23 × 3)/15
= – 35 + 69/15
= 34/15
Since there are no common factors other than 1 in the numerator and denominator
Thus, 34/15 Answer
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